Derfor bliver man skeptisk!

F. eks. forudsiger AGW at stratosfæren vil blive koldere, det observerer man...

I doubt that surface temperatures anomalies are as anomalously low as the mid-troposphere temperatures are running, which in combination with anomalously cold mid- and upper-tropospheric temperatures means there is extra energy available for storms. (Since AMSR-E failed in early October, our sea surface temperature plot is no longer showing current data, so I have no easy way to check surface temperatures.)
Of course, this too shall pass. I just thought it was an interesting curiosity during a time when some pundits are claiming global warming is "accelerating". Apparently, they are still stuck in the last millennium.

John Niclasen skrev:
når I argumenterer for, at MWP og LIA stort set var ikke-eksisterende, når man argumenterer for, at vi nærmest skal lukke al vores industri ned og betale en hulens masse penge til fattige stater, fordi det åbenbart er vores skyld, de har problemer, osv osv, så er det, at mange siger fra og bliver dybt skeptiske.

SRJ, du argumenterer for at det "er baseret på mindst 150 års seriøs forskning". Hvordan kan man så producere en hockey-stick graf? Den er kun 10-15 år gammel, og den viser ikke et sandt billede af virkeligheden, hvilket der er rigtig mange beviser for.

Klimaforskere skulle tale med nogle flere geologer og få perspektiv på klimaforandringerne. Og så skulle man se på alle konsekvenser af udledning af CO2. Det er jo plante-føde, vi snakker om.

SRJ skrev:
Jeg har aldrig argumenteret for at MWP og LIA ikke eksisterede. Jeg har påpeget at CO2science.org ikke er en god kilde til at belyse MWP og LIA fordi de misrepræsentere forskning.

Som man kan forvente med pioner-arbejde indenfor et felt, så har senere forskning nuanceret billedet noget mere, og hockeystavens skaft er blevet mere bugtet.

Geologer ser på klima-ændringer med tidsskalaer på millioner af år, og i dag oplever vi klima-ændringer med en noget kortere tidsskala. Så man skal nok være lidt varsom med sammenligninger.

Kosmos skrev:

F. eks. forudsiger AGW at stratosfæren vil blive koldere, det observerer man...

- på den anden side oberverer man ikke, at troposfærens mellemste/nedre lag bliver varmere (hvilket de ellers 'burde')


graf ---

Kjeld Jul skrev:
En oplistning af skandaler og fordrejninger af kendsgerninger,som gennem årene har gjort mig til skeptiker.
Tilhængerne af CO2 teorien og den etablerede videnskab omkring IPCC,kommer på overarbejde med deres skriftlige forklaringer,såfremt de vil klassificere alle disse skandaler som usande.

http://notrickszone.com/climate-scandals/

Vedr. grafen: Den fokuserer på kort-tids-ændringer. AGW manifesteres på lang skala

SRJ skrev:
Hvis man læser interviewet med Peter Ditlevsen er det klart det er en mistolkning af hans pointe.

SRJ skrev:
Nu hvor du har læst artiklen, er du så enig i at påstanden fra Notrickszone: "Climate models that purport to be sure are considered to be complete frauds" IKKE afspejler Peter Ditlevsens udtalelser?

John Niclasen skrev:

SRJ skrev:
Nu hvor du har læst artiklen, er du så enig i at påstanden fra Notrickszone: "Climate models that purport to be sure are considered to be complete frauds" IKKE afspejler Peter Ditlevsens udtalelser?

Jeg har ikke læst noget fra Notrickzone, men jeg er enig i, at "complete frauds" ikke er Ditlevsens mening om dem, som jeg læser ham.

Og jeg synes selv, det er at gå for vidt. Der er sikkert lagt meget arbejde i de modeller af også gode videnskabsfolk. Og man kan givet bruge dem til en masse godt, hvilket også folk som Lindzen siger. De bliver dog nok fortolket forkert eller for meget i nogle tilfælde. Computermodeller er ikke bedre, end hvad vi putter ind i dem.

Kosmos skrev:

F. eks. forudsiger AGW at stratosfæren vil blive koldere, det observerer man...

- på den anden side observerer man ikke, at troposfærens mellemste/nedre lag bliver varmere (hvilket de ellers 'burde')

---- graf af AMSU ch6

Jeg har downloadet hele datasættet og plottet dem som en sammenhængende tidsserie af anomalier ifht. perioden 2002-2012. Det ser ud til at der faktisk er et lille fald over tid i temperaturen målt i channel 6, men det er ikke statistisk signifikant. Så med udgangspunkt i disse data vil jeg ikke sige andet end at temperaturen i 7.5 km højde viser en stor variation fra år til år, men udviser ingen trend siden 2002

Kvinder og kvoter på forskere skal højne klimapanelets troværdighed
Det førende internationale klimapanel (IPCC) har valgt at indføre grænser for, hvor mange forskere der må være fra et givent område. Det sker i kølvandet på en sag, der har rokket ved panelets troværdighed. Dansk forsker hilser ændringerne velkommen.

Så med udgangspunkt i disse data vil jeg ikke sige andet end at temperaturen i 7.5 km højde viser en stor variation fra år til år, men udviser ingen trend siden 2002

Updated analyses using radiosonde data suggest RSS and STAR experienced spurious warming after the mid-1990s. When satellite and radiosonde data sets are considered, the global trends for 1979–2009 of the lower and mid-troposphere are +0.15 and +0.06° C decade^-1 respectively. Error ranges of these estimates, if we do not apply information that 15 indicates some data sets contain noticeable trend problems, are at least ±0.05°C decade^-1, which needs reduction to characterize forcing and response in the climate system accurately.

Boe Carslund-Sørensen skrev:
Mon ikke det er på tide at bede debattørerne om at holde sig til emnet for tråden:

Tråden titel er: Derfor bliver man skeptisk - SRJ, CBH m.fl. - hvad skal der til, for at du / I bliver skeptisk ?

I forhold til klimaet er afskaffelsen af støtte til fossile brændstoffer nævnt for første gang i et FN-dokument, og selvom dette afsnit ABSOLUT kunne være stærkere, vil vi vide at bruge det i det fremtidige arbejde. Afskaffede vi rent faktisk støtten til fossile brændstoffer i morgen, ville vi være halvvejs i mål i forhold til at nå de max to graders stigning...

Boe Carslund-Sørensen skrev:
Jeg og mange andre ved, at klimaet er total ligeglad med om CO2-udledningen kommer fra afbrænding af fossile eller biologiske brændsler...

Døde plantedele forrådner også ved angreb af mikroorganismer, men her er det det omgivende miljø, der bestemmer, om det bliver bakterier eller svampe, der udnytter fødekilden. Bakterierne er hurtige og effektive, men de er også krævende med hensyn til iltindhold, fugtighed, pH-forhold og indhold af biologisk brugbart kvælstof. Når disse forhold ikke er gunstige, overtages nedbrydningen af svampe, kan trænge langt ind med deres hyfer og opløse opløse plantestoffet. I realiteten opstår der en succession af bakterier og svampe, som omsætter og fordøjer hinandens affald.

http://da.wikipedia.org/wiki/Forr%C3%A5dnelse

Palle Miliam skrev:

Klimavidenskaben mangler en ordentlig review-proces og mere evidensbaseret forskning før den kan komme ud af sin vugge, bedst set ved følgende udsagn, hvor computermodeller forklare den manglende temperaturstigning de seneste 10-15 år med stigning i OCEAN HEAT CONTENT.

Dette kan forskere udenfor klimavidenskaben sagtens forstå, hvorfor kan dem, der er mest aktive indenfor klimavidenskaben det ikke?!

Enten er det fordi de er ualmindeligt dårlige til at forklare deres videnskab, således at folk, der i øvrigt er vandt til at begå sig i videnskabelig forskning undrer sig, eller også er de blevet forblindet af deres egen hypotese.



Jeg har tidligere i denne tråd henvist dig til en række andre observationer der er evidens for CO2-hypotesen. Det har du ikke forholdt dig til.
Jeg gentager gerne 3 af de observationer der er evidens for CO2-hypotesen:

- mindre temperatur-forskel mellem nat og dag og mellem sommer og vinter. Det er hvad man forventer fra en opvarming forårsaget af drivhusgasser.

- afkøling af stratosfæren er forventet, og observeres i den virkelige verden

- Satellitmålinger viser at der udsendes mindre varmestråling med bølgelængder svarende til CO2's absorbtionsbånd.

Referencer til peer reviewed forskning er her:
http://www.skepticalscience.com/10-Indicators-of-a-Human-Fingerprint-on-Climate-Change.html

Sidst men ikke mindst så viste jeg en graf der viser klimasystemets samlede energi-indhold. Det er steget og stiger stadig. Hvorfor nøjes med at se på OHC?

I øvrigt, så er klimavidenskaben ikke en ny videnskabsgren men er baseret på mindst 150 års seriøs forskning. Hvis du vil vide mere så søg på "Spencer Weart, Discovery of global warming"

Implications for the Earth's Energy Budget
[22] We follow the approach of Murphy et al. [2009] to
examine the Earth's energy balance. We use updates of
radiative forcing (F) from well‐mixed greenhouse gases and
fluctuations in solar radiation [Gregory and Forster, 2008]
(with the stratospheric ozone scaled as by Murphy et al.
[2009]) and volcanic aerosols from the Goddard Institute
for Space Studies (GISS) [Sato et al., 1993], updated at http://
data.giss.nasa.gov/modelforce/RadF.txt, and Gregory and
Forster [2008]. Integrated from 1961 through to the end of
2008, well‐mixed greenhouse gases, ozone and solar forcing
would result in the storage of 1,735 × 1021 J of additional heat
in the Earth's system if it were all retained (Figure 3). However,
as discussed in section 2, only 250 × 1021 J (234 from
1961–2008, 207 from 1972–2008) of the forcing is stored in
the Earth system (Figure 3a and Table 2), over 90% in the
ocean with minor storage in the atmosphere and the solid
earth and consumption in the melting of ice. Negative radiative
forcing from volcanic aerosols offset about 320 × 1021 J
(317 for GISS, 398 for Gregory and Forster [2008]) of
the greenhouse gas forcing. The remaining portion (1200 ×
1021 J; 1190 for the whole period, 1060 for 1972–2008)
must be balanced by the sum of reflection of solar radiation
by tropospheric aerosols and increased radiation from a
warming Earth.

Just how good are climate models at predicting regional patterns of climate change? I had occasion to survey this literature as part of a recently completed research project on the subject. The simple summary is that, with few exceptions, climate models not only fail to do better than random numbers, in some cases they are actually worse.

Looking at Fig 1 in Levitus et al (2012), showing the heat content of the ocean over time, the deeper layers (700 - 2000m) does increase post 2000 as does, at a greater rate, the 0 - 700m layer. However I would not say the gradient, or relative proportion of shallow and deep water heat partition, had changed post 2000. The data suggest that most of the heat has gone into the shallow regions (as to be expected) with the deeper regions warming slowly at a lower and unchanging rate since the start of the data in the mid-1950s. The plateau seen between 1980 - 90 is unexplained.



A major question is, of course, what happened before the mid-1950s? Only with such data can the modern increases in heat content be put into it proper context and anthropogenic influences detected from natural ones.

From this data we compute 25-year trends of nighttime
summertime/dry-season surface temperature using linear regression. The results indicate that the surface temperatures
of the studied water bodies have been rapidly warming with an average rate of 0.035 ± 0.011 °C/yr for the
period 1985–2011 and rates as high as 0.15 ± 0.01 °C/yr . Worldwide, the data show far greater warming in the midand
high latitudes than near the equator. The results provide a critical new independent data source on climate
change that indicates lake warming in certain regions is greater than expected based on air temperature data.

Average trend over all sites was found to be about 0.035 °C/yr or 0.35 °C/decade.

Palle Miliam skrev:

[Det sædvanlige om, at temperaturen har "stået stille" i de seneste ~15 års tid...]

Palle Miliam skrev:
Kære Kristoffer Haldrup

Min pointe i ovenstående er ikke de sidste 15 års stilstand, men en forundring over en poster, der slet ikke kommenterer dette, på trods af at enhver med lidt kritisk sans vil stille selvsamme spørgsmål ved et enkelt kig på grafen. Dette er netop hvad der gør mig skeptisk!

Palle Miliam skrev:

Når man så kigger på deres grafer så virker selvkritikken mangelfuld og dette er også blevet kommenteret andetsteds

World's Lakes Show Global Temperature Standstill
http://thegwpf.org/the-observatory/6060-worlds-lakes-show-global-temperature-standstill.html

Jeg synes dette viser meget klart, hvordan en mere skeptisk tilgang til data er ønskværdig.

Når Schneider et al bl.a. konkluderer:

Average trend over all sites was found to be about 0.035 °C/yr or 0.35 °C/decade.

og ikke bemærker, at den sidste halvdel af grafen (1997-2011) viser stationære temperaturer, så er det svært ikke at blive skeptisk!

Dear Dr Paul Bain,

Right now, it's almost my life's work to communicate the empirical evidence on anthropogenic climate change.

I can help you with your research on deniers. I have studied the mental condition of denial most carefully. There is a simple key to converting the convictions of people in this debate, and I have seen it work hundreds of times. Indeed, my own convictions that lasted 17 years were turned around in a few days. I can help you. It would be much simpler than you think.

Firstly, to save time and money we must analyze the leaders of the denial movement. I have emailed or spoken to virtually all of them.

They are happy to accept that CO2 is a greenhouse gas and causes warming, that humans produce CO2, that CO2 levels are rising, and that the earth has warmed in the last century. According to Hansen et al 1984, Bony et al 2006, and the IPCC AR4 report, the direct effect of doubling the level of CO2 amounts to 1.2°C (i.e. before feedbacks).

All they need is the paper with the evidence showing that the 1.2°C direct warming is amplified to 3 or 4 degrees as projected by the models. Key leaders in the denial movement have been asking for this data for years. Unfortunately the IPCC assessment reports do not contain any direct observations of the amplification, either by water vapor (the key positive feedback) or the totality of feedbacks. The IPCC only quotes results from climate simulations.

Since science is based on observations and measurements of the real world, it follows that a denier of science (rather than a denier of propaganda) must be denying real world data. I'd be most grateful if you could explain what "deniers" deny. Deniers repeatedly ask for empirical evidence, yet must be failing badly at communicating that this is the crucial point because none of the esteemed lead authors of IPCC working Group I seem to have realized that this paltry point is all that is needed. All this mess could be cleared up with an email.

The evidence for anthropogenic global warming is overwhelming, so the observations they deny must be written up many times in the peer review literature, right? After five years of study I am still not sure which instrument has made these key observations. Do deniers deny weather balloon results, or satellite data, or ice cores?

When you find this paper and the measurements, it will convince many of the key denier leaders. (But being the exacting personality type that they are, deniers will also expect to see the raw data. So you'll need to also make sure that the authors of said paper have made all the records and methods available, but of course, all good scientists do that already don't they?)

As a diligent researcher, I'm sure you would not have described a group with such an unequivocally strong label unless you were certain it applied. It would be disastrous for an esteemed publication like Nature to mistakenly insult Nobel prize winning physicists, NASA astronauts, and thousands of scientists who have asked for empirical evidence, only to find that the Nature authors themselves were unable to name papers (or instruments) with empirical evidence that their subject group called "deniers" denied.

If those papers (God forbid) do not exist, then the true deniers would turn out to be the researchers who denied that empirical evidence is key to scientific confidence in a theory. The true deniers would not be the skeptics who asked for evidence, but the name-calling researchers who did not test their own assumptions.

The fate of the planet rests on your shoulders. If you can find the observations that the IPCC can't, you could change the path of international action. Should you find the evidence, I will be delighted to redouble my efforts to communicate the empirical evidence related to climate change.

Awaiting your reply keenly,

Joanne Nova

Palle Miliam skrev:
Kære SRJ & Kristoffer

Jeg er helt enig i, at Davids indlæg også er farvet, men det er dog mere forståeligt, når nu posteren er så mangelfuld, hvad kritisk sans angår.
Jeg vil godt lige fastholde, at her har vi nogle forskere, der angiveligt prøver at fastholde AGW-hypotesen og det virker gang på gang som om de ikke evner en kritisk tilgang hertil, det får ihvertfald mig i blækhuset!

[the leaders of the denial movement] are happy to accept that CO2 is a greenhouse gas and causes warming,

Der CO2-Treibhauseffekt der Erdatmosphäre ist eine reine Fiktion von Leuten, die gerne große Computer benutzen, ohne physikalische Grundlagen.

that humans produce CO2,

...stigning av både CO2 og temperatur over hele tidsrommet 1958-2011 [...] kan på enkelt vis forklares med frigivelse av CO2 fra havene på grunn av stigende temperatur.

The long-term increases in carbon dioxide concentration that have been observed at Mauna Loa since 1958 could be driven more than by the ocean than by mankind's burning of fossil fuels.

that CO2 levels are rising,

- Atmospheric co2 level was higher in the early 20th century
- Ice core co2 histories are wrong

Direct atmospheric measurements indicate that between 1812 and 1961, the concentrations of CO2 fluctuated by about 150 ppmv, up to values much higher than those of today.

and that the earth has warmed in the last century.

[L]eading meteorological institutions in the USA and around the world have so systematically tampered with instrumental temperature data that it cannot be safely said that there has been any significant net "global warming" in the 20th century.

...since 1940 it's been cooling down. The evidence for warming is because of distorted records. The satellite data, for example, shows cooling.

Unfortunately the IPCC assessment reports do not contain any direct observations of the amplification, either by water vapor (the key positive feedback)....

When you find this paper and the measurements, it will convince many of the key denier leaders. (But being the exacting personality type that they are, deniers will also expect to see the raw data. So you'll need to also make sure that the authors of said paper have made all the records and methods available, but of course, all good scientists do that already don't they?)

I'm prepared to accept whatever result they produce, even if it proves my premise wrong.

der ikke tror på at CO2 og andre drivhusgasser har en opvarmende effekt

"jeres" side groft sagt bliver skåret over een kam og lagt i kategorien "ikke værd at spilde tid på"

John Niclasen skrev:
@Palle

Der er god grund til bekymring! Læg mærke til al fordrejningen, vi hele tiden er vidne til. Jeg har tilladt mig at stille spørgsmålstegn ved nogle grundlæggende ting. Jeg tror ikke på videnskab, for videnskab er ikke et spørgsmål om tro. Når jeg stiller spørgsmål, bliver jeg klogere. Fordi jeg har tilladt mig at stille spørgsmål, bliver jeg nu konstant mødt med udsagn som:

der ikke tror på at CO2 og andre drivhusgasser har en opvarmende effekt

Jeg mindes ikke, jeg nogensinde har udtrykt, at jeg tror noget sådant. Men selvfølgelig skal mine ord fordrejes igen og igen, for jeg stiller jo spørgsmålstegn ved "konsensus". Jøsses!

Og videre skrives der:

"jeres" side groft sagt bliver skåret over een kam og lagt i kategorien "ikke værd at spilde tid på"

Kig så på, hvor meget tid og hvor mange kræfter, der bruges på at forsøge at lukke munden på dem, der i god videnskabelig stil tillader sig at stille spørgsmålstegn ved teorierne. Læg mærke til, hvor nedladende, det ofte er. Holder ens argumenter ikke, kan man jo altid svine "modstanderen" til.

Et af problemerne er, at de ser det som en kamp, og ikke som en diskussion mellem voksne mennesker.

Jeg har sagt det før, og jeg bliver mere og mere overbevist: Teorien om katastrofal menneskeskabt global opvarmning er et paradigme, som beskrevet af Kuhn. Sådanne paradigmer har flere paralleller med religion end med videnskab. Der skal kritisk rationalisme, som beskrevet af Popper, til at gøre kål på det.

Først snakkede man om "Global opvarmning", siden om "Klimaforandringer", og det begreb er nu ved at blive udskiftet med "Bæredygtighed" og lign., som man kan se af klimarelaterede konferencer, som den for nylig i Rio. Der ligger også en anden "katastrofe" og lurer, nemlig påstanden om forsuring af havene.
.

??? Her er tre klassiske artikler (hvoraf i hvert fald de to har været citeret i IPCC-rapporterne), som alle ganske simpelt har målt positiv feedback fra vanddamp efter El Niño, efter Pinatubos udbrud, eller generelt over årene 1982-2004.

Observations of the clear-sky outgoing longwave radiation and sea surface temperature are combined to examine the evolution of the tropical greenhouse effect from colder La Niña conditions in early 1985 to warmer El Niño conditions in late 1987. Although comparison of individual months can suggest a decrease in greenhouse trapping from cold to warm conditions, when the entire 4-yr record is considered a distinct increase in tropical-mean greenhouse trapping of 2 W m−2 is observed in conjunction with a 0.4 K increase in tropical-mean sea surface temperature. This observed increase compares favorably with GCM simulations of the change in the clear-sky greenhouse effect during El Niño–Southern Oscillation (ENSO). Superimposed on top of the SST-driven change in greenhouse trapping are dynamically induced changes in tropical moisture apparently associated with a redistribution of SST during ENSO. The GCM simulations also successfully reproduce this feature, providing reassurance in the ability of GCMs to predict both dynamically and thermodynamically driven changes in greenhouse trapping.


Received: July 18, 1996; Revised: October 1, 1996

Thus, while the observational results presented here may not be directly interpreted as a measure of water vapor feedback, the high degree of similarity between the observed and modeled variations in tropical greenhouse forcing during ENSO provides reassurance in the ability of the GCM to correctly predict this relationship under global warming scenarios.

The sensitivity of Earth's climate to an external radiative forcing depends critically on the response of water vapor. We use the global cooling and drying of the atmosphere that was observed after the eruption of Mount Pinatubo to test model predictions of the climate feedback from water vapor. Here, we first highlight the success of the model in reproducing the observed drying after the volcanic eruption. Then, by comparing model simulations with and without water vapor feedback, we demonstrate the importance of the atmospheric drying in amplifying the temperature change and show that, without the strong positive feedback from water vapor, the model is unable to reproduce the observed cooling. These results provide quantitative evidence of the reliability of water vapor feedback in current climate models, which is crucial to their use for global warming projections.

Climate models predict that the concentration of water vapor in the upper troposphere could double by the end of the century as a result of increases in greenhouse gases. Such moistening plays a key role in amplifying the rate at which the climate warms in response to anthropogenic activities, but has been difficult to detect because of deficiencies in conventional observing systems. We use satellite measurements to highlight a distinct radiative signature of upper tropospheric moistening over the period 1982 to 2004. The observed moistening is accurately captured by climate model simulations and lends further credence to model projections of future global warming.

They are happy to accept that CO2 is a greenhouse gas and causes warming, that humans produce CO2, that CO2 levels are rising, and that the earth has warmed in the last century. According to Hansen et al 1984, Bony et al 2006, and the IPCC AR4 report, the direct effect of doubling the level of CO2 amounts to 1.2°C (i.e. before feedbacks).

All they need is the paper with the evidence showing that the 1.2°C direct warming is amplified to 3 or 4 degrees as projected by the models. Key leaders in the denial movement have been asking for this data for years. Unfortunately the IPCC assessment reports do not contain any direct observations of the amplification, either by water vapor (the key positive feedback) or the totality of feedbacks. The IPCC only quotes results from climate simulations.

Prescott's terrifying warnings were backed by Britain's leading climate scientists. Just before Kyoto a Met Office report warned that climate-related floods would put 50m people at risk of death from starvation in the coming decades. Whole island nations would disappear, it added, while the American Midwest, which helps to feed 100 nations, was likely to face drought and the North Pole might melt.

That was 15 years ago — what has happened to world temperatures since then? Last month came the suggestion that the answer was, embarrassingly, nothing. Research based on Met Office figures pointed to temperatures having been flat since 1997.


Whitehouse accepts this point. "The records do show that global temperatures have risen by about 0.4C over the past three decades, most of it in the 1990s," he said.

"I accept that CO2 is a greenhouse gas that might warm the world but the key issue is how strong the effect is and how the data compare with the models used to predict the future."



Længere nede i artiklen


For the critics of climate science this is a crucial point — but why? The answer goes back to the 2001 and 2007 science reports from the Intergovernmental Panel on Climate Change that had predicted the world was likely to warm by an average of about 0.2C a decade. The implication was that temperatures would rise steadily, not with 15-year gaps. The existence of such gaps, the critics argue, implies the climate models themselves are too flawed to be relied on.

Så når David Whitehouse (og du) påstår at den dataserie er flad fra 1997-2011, og trenden dermed forskellig ifht. perioden op til 1997 så det jer der ikke er kritiske nok. På mig virker det som om du har en forudfatttet mening om trenden nok flader ud fra omkring 1998, og så ser du på grafen og siger "det passer da meget godt". Det gør det kun hvis du smider ca. halvdelen af dataserien væk. Og den går altså ikke.

A sizeable (and growing) proportion of the public in Western democracies deny the existence of anthropogenic climate change1, 2. It is commonly assumed that convincing deniers that climate change is real is necessary for them to act pro-environmentally3, 4. However, the likelihood of 'conversion' using scientific evidence is limited because these attitudes increasingly reflect ideological positions5